Emax USA

EMAX ECOII 4215 Brushless Motor

$27.99 USD Sold out
KV
Notes
ECO II SERIES / LARGE MULTIROTOR POWER
Brushless Motor Platform

EMAX ECO II 4215

The EMAX ECO II 4215 is a high-output brushless motor platform for 13-inch multirotor propellers. Four winding options—350KV, 420KV, 520KV and 660KV—cover 6S through 12S power systems, while the 12N14P architecture, 49.1mm diameter, 65.35mm length, M6 threaded propeller shaft and 30 × 30mm mounting pattern provide a practical foundation for large multirotor propulsion.

Four KV options. One 4215 platform. 350KV for 6S–12S high-voltage systems. 420KV for 6S–10S power systems. 520KV for 6S–8S configurations. 660KV for responsive 6S configurations.
Motor weight209–210gExcluding silicone wire
System range6S–12SKV-dependent battery support
Propeller13"Published platform specification
Framework12N14PLarge outrunner architecture
EMAX ECO II 4215 brushless motor for 13-inch multirotors with 350KV, 420KV, 520KV and 660KV options

High-voltage 13-inch propulsion. The 350KV configuration supports up to 12S, and the supplied 48V bench test recorded as much as 8.13kg of thrust with an HQ 1309 three-blade propeller.

01 / KV Selection

Match voltage and winding to the aircraft.

Published electrical limits come from the supplied EMAX specification workbook. Tested thrust values are the highest recorded values in the matching load-test workbooks.

350KV
6S–12S / 13-inch propeller
Lowest-KV option for the widest voltage range.
Peak current71A @ 12S
Max power3408W
Resistance62mΩ
Idle current1.0A @ 10V
Bench highlight: 8.13kg thrust at 48V with HQ 1309 three-blade; 70.7A / 3393.6W.
420KV
6S–10S / 13-inch propeller
Balanced high-voltage option for large multirotors.
Peak current81A @ 10S
Max power3240W
Resistance49mΩ
Idle current1.2A @ 10V
Bench highlight: 7.84kg thrust at 40V with HQ 1309 three-blade; 80.6A / 3224W.
520KV
6S–8S / 13-inch propeller
Higher-RPM option for medium-voltage systems.
Peak current75A @ 8S
Max power2400W
Resistance38mΩ
Idle current1.9A @ 10V
Bench highlight: 6.35kg thrust at 32V with HQ 1309 three-blade; 73.9A / 2364.8W.
660KV
6S / 13-inch propeller
Highest-KV winding for dedicated 6S systems.
Peak current90A @ 6S
Max power2250W
Resistance26mΩ
Idle current2.3A @ 10V
Bench highlight: 5.98kg thrust at 25V with HQ 1309 three-blade; 85.3A / 2132.5W.
EMAX ECO II 4215 KV selection guide for 350KV, 420KV, 520KV and 660KV motors with 13-inch propellers
Swipe horizontally to compare all four KV options

Choose from the complete aircraft backward. Match motor KV to battery voltage, propeller load, ESC rating, aircraft mass, airflow and required thrust. Published ranges are selection guidance; validate the final power system under realistic thermal conditions.

02 / Performance Envelope

Maximum tested thrust by KV.

Each bar shows the highest thrust recorded in the supplied test workbook for that winding. All bars share an 8.13kg scale.

350KV48V
8.13kg
420KV40V
7.84kg
520KV32V
6.35kg
660KV25V
5.98kg

Maximum values above were recorded with an HQ 1309 three-blade propeller. Bench results are configuration-dependent and are not guaranteed aircraft-level performance.

03 / Construction

Practical hardware for sustained multirotor loads.

01 / SHAFT

Steel Shaft

Steel shaft construction supports the long M6 threaded propeller interface used by the 4215 platform.

02 / FINISH

Anodized Structure

Anodized metal surfaces provide a durable finish for regular installation and service.

03 / MOUNT

30 × 30mm Pattern

A four-hole 30 × 30mm mounting pattern provides a defined mechanical interface for the airframe.

04 / WINDING

Multi-Strand Winding

Multi-strand winding is specified for the high-current operating range of this large outrunner.

05 / BEARING

Precision Bearing

Precision bearing hardware supports smooth rotation under sustained propeller load.

06 / LEADS

300mm 16 AWG Wire

Long silicone motor leads provide routing flexibility during large-airframe power-system installation.

Exploded EMAX ECO II 4215 outer-rotor motor showing the steel M6 shaft, anodized rotor bell, full-height 14-pole magnet ring, 12-slot wound stator, precision bearing and 30 by 30 millimeter motor mount
Swipe horizontally to inspect the component callouts
04 / Mechanical Data

4215 geometry and installation details.

Motor model EMAX ECO II 4215
Framework 12N14P
Motor diameter Ø49.1mm
Motor length 65.35mm
Weight 209g; 660KV listed at 210g, without silicone wire
Bearing shaft Ø6mm
Propeller shaft M6 threaded
Shaft direction CW thread
Mounting pattern 30 × 30mm, four-hole
Motor leads 300mm 16 AWG silicone wire
Propeller specification 13 inches
KV options 350KV / 420KV / 520KV / 660KV
One platform, four voltage profiles.

The shared mechanical package makes it possible to select a winding around the intended voltage without changing the motor's basic airframe interface.

The published 6S–12S envelope belongs to the complete product family. Each individual KV option has its own cell-count limit shown in the electrical table below.

Installation note: Confirm frame clearance, screw engagement, propeller retention, ESC headroom and cooling before operation.

EMAX ECO II 4215 large multirotor motor platform with four KV options

Performance without unnecessary complexity. The ECO II 4215 combines a consistent mechanical platform with four winding choices for large multirotor builders who need to match voltage, current and thrust targets.

05 / Electrical Specifications

KV-specific operating limits.

Use only the voltage range published for the selected winding. The 520KV and 660KV cell references below are reconciled with the supplied 32V and 25V test files and the published maximum-power values.

KV Cells Propeller Idle Current Resistance Peak Current Max Power
350KV 6S–12S 13" 1.0A @ 10V 62mΩ 71A @ 12S 3408W @ 12S
420KV 6S–10S 13" 1.2A @ 10V 49mΩ 81A @ 10S 3240W @ 10S
520KV 6S–8S 13" 1.9A @ 10V 38mΩ 75A @ 8S 2400W @ 8S
660KV 6S 13" 2.3A @ 10V 26mΩ 90A @ 6S 2250W @ 6S
06 / Bench Data

Maximum recorded propeller results.

The expandable tables show the final, highest-load row from each propeller set in the supplied workbooks.

350KV Load-Test Highlights48V / Three propellers
Voltage Propeller Current Thrust Power Efficiency
48V Gemfan 1310, 3-blade 62.2A 7500g 2985.6W 2.51g/W
48V HQ 1309, 3-blade 70.7A 8130g 3393.6W 2.40g/W
48V 13 × 4 carbon-fiber, 2-blade 36.2A 6080g 1737.6W 3.50g/W

Final recorded row from each 350KV propeller series. RPM was marked "Max" rather than numerically reported at these endpoints.

420KV Load-Test Highlights40V / Three propellers
Voltage Propeller Current Thrust Power Efficiency
40V Gemfan 1310, 3-blade 71.3A 7250g 2852W 2.54g/W
40V HQ 1309, 3-blade 80.6A 7840g 3224W 2.43g/W
40V 13 × 4 carbon-fiber, 2-blade 42.0A 5780g 1680W 3.44g/W

Final recorded row from each 420KV propeller series. RPM was marked "Max" rather than numerically reported at these endpoints.

520KV Load-Test Highlight32V / HQ 1309
Voltage Propeller Current Thrust Power Efficiency
32V HQ 1309, 3-blade 73.9A 6350g 2364.8W 2.69g/W

Final recorded row from the supplied 520KV load-test series.

660KV Load-Test Highlight25V / HQ 1309
Voltage Propeller Current Thrust Power Efficiency
25V HQ 1309, 3-blade 85.3A 5980g 2132.5W 2.80g/W

Final recorded row from the supplied 660KV load-test series.

EMAX ECO II 4215 motor package with four M4 by 12 millimeter screws, steel M6 nylock nut and propeller washer

Package contents: one EMAX ECO II 4215 brushless motor, four M4 × 12mm screws, one steel M6 nylock nut and one propeller washer.

07 / In The Box

Core installation hardware included.

EMAX ECO II 4215 brushless motor
M4 × 12mm mounting screws
Steel M6 nylock nut
Propeller washer

Bench-test note: Performance values are measured test data, not guaranteed aircraft-level performance. Current draw, thrust, efficiency, RPM and temperature vary with propeller, battery voltage and sag, ESC behavior, airflow, ambient conditions and test equipment. Select the motor winding, propeller, ESC, battery and cooling appropriate for the complete aircraft.

Product information

All parts are shipped fast from SYRACUSE, NEW YORK & some DROP SHIP ORDERS from San Diego, California. If there's an issue with something, please let us know and we will do our best make it right! SaltCtyRacingFPV, LLC dba "weBLEEDfpv.com" offers a (30) day return policy on all new unopened equipment, starting from the date the product(s) was delivered to the customer. Anything beyond (30) days of delivery will not be eligible for return. If the product(s) received have been opened, used or damaged, no return options will be offered. If the item is in brand new condition but requires to be repackaged, a (15%) restocking fee will be applied. The shipping cost for any unwanted product will not be refunded by SaltCtyRacingFPV "weBLEEDfpv.com" (It is recommended to choose a return shipping method with tracking).

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Bench setup without airflow/cooling can result in excessive heat buildup.

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